free radical

Từ điển WordNet v3.1 - WordNet Dictionary

noun

an atom or group of atoms with at least one unpaired electron;
in the body it is usually an oxygen molecule that has lost an electron and will stabilize itself by stealing an electron from a nearby molecule (Freq. 2)
- in the body free radicals are high-energy particles that ricochet wildly and damage cells
• Syn:
radical
• Hypernyms:
atom